Cylinder for opposed piston engines



c. RETSCHY ciLINDER ,FOR OPPOSED PISTON ENGINES March 19, 1940.

Filed Aug. 2'7, 193? m mm Wm m3 AM J M w 6 5 A m 6% M M H. 5 I

' Patented Mar. 19, 1940 mm STATES- has cynmnsa For; orrosao ris-rou enemas Curt Retschy, Wintertlmr, Switserland, assignor to-Sulzer Freres, Socit Anonyme, Winterthur,

Switzerland Application August a7, 1937, Serial No. 161,195 In Switzerland September 22, 1936 Claims. (Cl. 123-173) This invention relates toan improved cylinderfor opposed-piston engines and has for its prin-. cipal object the provision of a cylinder-liner having means for preventing local overheating of the I I liner. My invention makes it possible to maintain the temperature of the cylinder substantially uniform and the undesirable consequences oi temperature inequalities are, therefore, largely eliminated.

In cooling opposed-piston engines, it is' de sirable to maintain the temperature of the-cylinderwalls as nearly uniform as possible in order to minimize heat stresses within the cylinder which will tend to impair the eflicient operation of the piston andpiston rings. Lack of uniformity oi! the cylinder wall temperatures is due largely to the high temperatures created in the combustion chamber of the engine and to the relatively low temperatures prevailing at the I. extremities of the cylinder. In apparatus heretofore proposed for cooling the cylinders of opposed-piston engines, the cooling effect or the rate of heat dissipation has been substantially uniform throughout the length or the cylinder. Consequently that portion or the cylinder which surrounds the combustion chamber has been 'kept at a considerably higher temperature than I 49 may be shaped and positioned in various ways.

1 for example, they may be angular and positioned so that their vertices are at substantially the longitudinal. center of the annular projection or they may be straight and positioned obliquely to the [axis of the cylinder.

The constructional details of my invention are shown in the accompanying drawing, in which:

Fig. 1 is a sectional view, partly in section, of

lo a cylinder assembly illustrating a. cylinder-liner in accordance with my invention;

Fig.2 is a view, partly in section, of a'cylinderliner illustrating another embodiment of my invention;

Pk. 3 is asection along the line 3-4 01' Pig. 1;

Fig. 4 is a section'along the line |4 of Fig. 2, and

Fig. 5 is a section along the line 5-5 of Fig. 2.

As shown in the drawing, the cylinder-liner I is provided with a scavenging port 2 and an 5 exhaust port 3. The piston's l'and 5 are shown in their outer dead-center positions. when the pistons are in their inner dead-center positions, the space between them serves as the combustion chamber of the engine. The cylinder-liner l 10 is held in place by the flanges 8 of the cylinder jacket 1 which is providedwith bores 6 within which suitable fuel valves (not shown) may be arranged.

A cooling medium, for example water, which 16 enters through the opening 16a and discharges through the opening I6b' flows through the passages 9 and I0. These passages are connected to one another by the angular channels 13 and H in the collar or annular projection i8 which encircles the combustion chamber. The channels l3 and H form a pair of inclined intersecting channels, and a plurality of such pairs of channels are formed in the annular projection. Those portions of the collar or annular projection which are penetrated by theiuel and starting valves are provided with channels H and I2 which are connected together or by-passed by the space l5 surrounding these valves.

The angular channels l3 and H are inclined toward the axis of the cylinder so that the distance between each of the angular channels and the inner bore of the cylinder becomes a minimum at substantially the center of the annular projection I 8, i. e.'the center with respect to the length 'of the annular projection as determined, for-example, by the position of the line 3-3 in Fig. 1 and line 4-4 in Fig. 2. Each of the angular channels slopes from each end towards the cylinder wall and the vertex is adjacent 40 the center of the projection I8. The chanbe readily determined by reference to Fig. 3.

'Inthe embodiment of my invention shown in Fig. 2 the channels I! passing through the annular projection of the cylinder-liner I are arranged obliquely to the axis of the cylinder and are straight instead of being angular. The, man- ,ner in which these channels H 'are placed in the annular projection ll is'shown in Figs. 4 and 5.

As shown in the lower portion of Fig. 2, the channels I I are nearest the inner bore of the cylinder where they approach the center of the annular projection II. This is further illustrated by reference to Figs. 4 and 5 which show that each individual channel is at its minimum distance from the inner bore of the cylinder at substantially the center of the annular projection. On either side of this center, the distance between the inner bore of the cylinder and the channels increases. At those places where the annular projection is penetrated by the fuel and starting valves, the channels H are cut short and are by-passed in thesame fashion as channels H and i2, shown in Fig. 1.

By maintaining the temperature of the cylinder wall substantially uniform, I am able to reduce and minimize the strains and stresses which result from non-uniform temperatures in the cylinder, While I have shown two embodiments of the invention by which a substantial uniformity of temperature may be attained in the cylinder-liner, I do not wish to be limited thereto, since my invention includes any construction of channel in the annular projection of the cylinder in which the distance between the channel and the inner bore of the cylinder;

where the fuel and starting valves penetrate the annular projection.

4. A cylinder-liner as claimed in claim 2 in which the channels are by-passed at the places where the fuel and starting valves penetrate the annular projection.

5. A cylinder-liner for dpposed-piston engines having a collar or projection on the outside thereof, the center of said projection embracing a plane at right angles to the longitudinal axis of the cylinder-liner and midway between the pistons, a plurality of pairs of inclined intersecting channels in the projection for the circulation therein of a cooling medium which are so disposed that the points of intersection of the channels come closest to the inner wall of the cylinder-liner near the said center, an opening in the liner projection for the mounting of valve means, other channels in the projection adjacent theopening, and a passage surrounding the opening connected to the other channels for circulating cooling medium through the other channels and the passage. CURT RETSCHY. 

